1. Field of the Invention
The present invention relates to a conversion plug structure having a variable resistor, and more particularly, to a conversion plug structure connecting with an end of a power cord and providing various voltages via adjusting a variable resistor of an intermediate adaptor thereof.
2. Background of the Invention
Referring to FIG. 1, a conventional DC power cord 70 can connect with a conversion plug structure 80. The conversion plug structure 80 includes an intermediate adaptor 81 connecting with an end of the power cord 70 and a changeable conversion adaptor 82. The intermediate adaptor 81 has three insertion holes 83 at an end thereof and three first terminals 84 respectively disposed in the insertion holes 83 and electrically connecting with the power cord 70. The conversion adaptor 82 has second terminals 85 disposed at an end thereof. The second terminals 85 of the conversion adaptor 82 are capable of inserting in the corresponding insertion holes 83 of the intermediate adaptor 81, so that the second terminals 85 respectively electrically connect with the first terminals 84. Therefore, the conversion adaptor 82 connects with the intermediate adaptor 81 in an insertion and a changeable manner, the conversion adaptor 82 electrically connects with the intermediate adaptor 81 and the power cord 70, and electric power is transmitted to the conversion adaptor 82 via the power cord 70 and the intermediate adaptor 81.
Because the conversion adaptor 82 connects with the power cord 70 in a changeable manner, when the power cord 70 is used for different specifications of outlets of electric appliances, the conversion adaptor 82 can be changed to apply to various outlets without changing the power cord 70, thereby reducing fabrication costs and consumers' expenses.
The above power cord 70 can be applied to only one kind of voltage, but general electric appliances have various ranges of voltages including 15V, 16V, 17V, 19V, 20V, 22V, etc. Therefore, the power cord 70 does not have a widespread use.
FIG. 2 shows another conventional conversion plug structure 80. The conversion adaptor 82 is further divided into a first body 86 and a second body 87. The first body 86 and the second body 87 are connected with each other via a connection cord 88. A resistor (not shown) is disposed inside the conversion adaptor 82 in a proper position thereof. The voltage of the electric power transmitted by the power cord 70 can be changed via the resistor inside the conversion adaptor 82, and the conversion adaptor 82 can be changed to provide various voltages for various electric appliances without changing the power cord 70, thereby obtaining a widespread use. However, the conversion adaptor 82 has to be changed, so as to have different resistances, which increases costs and consumer' expenses.
Accordingly, as discussed above, the conventional conversion plug structure still has some drawbacks that could be improved. The present invention aims to resolve the drawbacks in the prior art.